TIL, 2017-03-08

Designing API endpoints: Try to provide as much to the client as possible.
To organize/group selected models, get all first, then do the group_by, because group_by removes their AR parts and turns them into arrays.
The back-end will adjust to the front-end if possible. When thinking of how APIs are supposed to be structured, look at the solid APIs (Stripe, Github, etc.)
Do not be a condescending fuck.
Major major thinking point/important thing when reasoning about code is that if it is something that is expected to change at some point. Think of what will break if things change.
Joining using ActiveRecord is not as hard as you think, just practice it and check the generated SQL by to_sql.